I just had a frenectomy and fiberotomy. will the space close up?

Probably not: Frenectomy and fiberotomy removes abstruction but you still have to make effort in closing spaces.

No: The frenectomy and fiberotomy are often performed to help in the closure of a diastema (space between the teeth), and are usually done in conjunction with some type of orthodontic movement of the teeth to close the space.

After braces: Spaces do not usually close by itself. Time depends on your teeth, jaw, bite and other factors.

As force is applied: I must assume that you are also having concurrent orthodontic treatment with braces or clear aligners. The space will not likely spontaneously close - some type of orthodontic force will be required. Depending upon the size of your diastema or space, it can typically be closed within weeks.